You cannot use the parameters apache_custom_http or apache_custom_https
Except my this, it is good.
Those parameters requires approval and review from the instance owner (if you are using VIFIB, you must open a ticket for this), so if you request like this you get probably blocked. (this is like this for security reasons).
I think you can request several slaves for the same thing, and using "url" and "path" parameters.